drivers/misc/vmw_balloon.c

File Facts

System

Linux kernel

Corpus path

drivers/misc/vmw_balloon.c

Extension

.c

Size

52860 bytes

Lines

1874

Domain

Driver Families

Bucket

drivers/misc

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/types.h
• linux/io.h
• linux/kernel.h
• linux/mm.h
• linux/vmalloc.h
• linux/sched.h
• linux/module.h
• linux/workqueue.h
• linux/debugfs.h
• linux/seq_file.h
• linux/rwsem.h
• linux/slab.h
• linux/spinlock.h
• linux/balloon.h
• linux/vmw_vmci_defs.h
• linux/vmw_vmci_api.h
• asm/hypervisor.h

Detected Declarations

• struct vmballoon_ctl
• struct vmballoon_batch_entry
• struct vmballoon
• struct vmballoon_stats
• enum vmwballoon_capabilities
• enum vmballoon_page_size_type
• enum vmballoon_op
• enum vmballoon_op_stat_type
• enum vmballoon_cmd_type
• enum vmballoon_error_codes
• enum vmballoon_stat_page
• enum vmballoon_stat_general
• function is_vmballoon_stats_on
• function vmballoon_stats_op_inc
• function vmballoon_stats_gen_inc
• function vmballoon_stats_gen_add
• function vmballoon_stats_page_inc
• function vmballoon_stats_page_add
• function __vmballoon_cmd
• function vmballoon_cmd
• function vmballoon_send_start
• function vmballoon_send_guest_id
• function vmballoon_page_order
• function vmballoon_page_in_frames
• function vmballoon_mark_page_offline
• function vmballoon_mark_page_online
• function vmballoon_send_get_target
• function vmballoon_alloc_page_list
• function vmballoon_handle_one_result
• function vmballoon_status_page
• function page
• function vmballoon_add_page
• function pages
• function vmballoon_release_page_list
• function list_for_each_entry_safe
• function vmballoon_release_refused_pages
• function vmballoon_change
• function vmballoon_enqueue_page_list
• function list_for_each_entry
• function vmballoon_dequeue_page_list
• function vmballoon_split_refused_pages
• function list_for_each_entry_safe
• function vmballoon_inflate
• function vmballoon_deflate
• function vmballoon_deinit_batching
• function vmballoon_init_batching
• function vmballoon_doorbell
• function vmballoon_vmci_cleanup

Annotated Snippet

* Using late_initcall() instead of module_init() allows the balloon to use the
 * VMCI doorbell even when the balloon is built into the kernel. Otherwise the
 * VMCI is probed only after the balloon is initialized. If the balloon is used
 * as a module, late_initcall() is equivalent to module_init().
 */
late_initcall(vmballoon_init);

static void __exit vmballoon_exit(void)
{
	vmballoon_unregister_shrinker(&balloon);
	vmballoon_vmci_cleanup(&balloon);
	cancel_delayed_work_sync(&balloon.dwork);

	vmballoon_debugfs_exit(&balloon);

	/*
	 * Deallocate all reserved memory, and reset connection with monitor.
	 * Reset connection before deallocating memory to avoid potential for
	 * additional spurious resets from guest touching deallocated pages.
	 */
	vmballoon_send_start(&balloon, 0);
	vmballoon_pop(&balloon);
}
module_exit(vmballoon_exit);

Annotation

• Immediate include surface: `linux/types.h`, `linux/io.h`, `linux/kernel.h`, `linux/mm.h`, `linux/vmalloc.h`, `linux/sched.h`, `linux/module.h`, `linux/workqueue.h`.
• Detected declarations: `struct vmballoon_ctl`, `struct vmballoon_batch_entry`, `struct vmballoon`, `struct vmballoon_stats`, `enum vmwballoon_capabilities`, `enum vmballoon_page_size_type`, `enum vmballoon_op`, `enum vmballoon_op_stat_type`, `enum vmballoon_cmd_type`, `enum vmballoon_error_codes`.
• Atlas domain: Driver Families / drivers/misc.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.